aside{
    position: fixed;
    right: 2em;
    top: 2em;
    bottom: 2em;
}

ul{
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    height: 100%;
    margin: 0;
    padding-left: 0;
    list-style: none;
}
section{
    height: 5em;
    border-bottom: 1px solid #ccc;
}